A 15-month-old boy and the father who abducted him in Boyle Heights are believed to be in Sonora, Mexico and authorities are urging the man to return to the United States and surrender.

An Amber Alert was issued after the boy was allegedly abducted by his non-custodial father on Tuesday in the Boyle Heights area, Los Angeles police said.

The child was believed to have been taken by his father, Carlos Ivan Reyna Lara, on the same day he was told by a judge that Department of Children and Family Services would be taking custody of the boy. Police said the parents were in court on a narcotics-related issue when they lost custody.

DCFS officials went to the parents' home in the 2000 block of E. Fourth Street to pick up the boy, identified as Noe Reyna, when they realized the child was gone, as well as his father, investigators said.

The child was last seen at the home with his father at about 4 p.m. Tuesday. He was in a red stroller that his father was pushing.

Authorities now believe he fled to Mexico with the boy and is staying with family there. They have been unable to contact him or determine exactly how he was able to cross the border after the Amber Alert had been issued.

They do not believe the father intends harm to his son.

"As far as we know the child is not in any imminent danger," said LAPD Detective Liliana Preciado.

Noe Reyna is described as 2 feet tall, about 35 pounds, with black hair and brown eyes. He was last seen wearing a yellow shirt, black tennis shoes and black shorts with two green stripes.

Police released a photo of Carlos Reyna, who has a dark mustache in the image.

Authorities said the father's background doesn't indicate there would be any danger to the child, though they aren't discussing why the parents lost custody.

"The sooner he comes back to the United States, the better it is," Preciado said.

Anyone with information about Noe's whereabouts is asked to call 911 or detectives from the LAPD's Hollenbeck Division at (323) 342-4101.